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-rw-r--r--dosfstools/src/io.c230
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diff --git a/dosfstools/src/io.c b/dosfstools/src/io.c
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+/* io.c - Virtual disk input/output
+
+ Copyright (C) 1993 Werner Almesberger <werner.almesberger@lrc.di.epfl.ch>
+ Copyright (C) 1998 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ On Debian systems, the complete text of the GNU General Public License
+ can be found in /usr/share/common-licenses/GPL-3 file.
+*/
+
+/*
+ * Thu Feb 26 01:15:36 CET 1998: Martin Schulze <joey@infodrom.north.de>
+ * Fixed nasty bug that caused every file with a name like
+ * xxxxxxxx.xxx to be treated as bad name that needed to be fixed.
+ */
+
+/* FAT32, VFAT, Atari format support, and various fixes additions May 1998
+ * by Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> */
+
+#define _LARGEFILE64_SOURCE
+#include <sys/types.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fd.h>
+
+#include "dosfsck.h"
+#include "common.h"
+#include "io.h"
+
+typedef struct _change {
+ void *data;
+ loff_t pos;
+ int size;
+ struct _change *next;
+} CHANGE;
+
+static CHANGE *changes, *last;
+static int fd, did_change = 0;
+
+unsigned device_no;
+
+#ifdef __DJGPP__
+#include "volume.h" /* DOS lowlevel disk access functions */
+loff_t llseek(int fd, loff_t offset, int whence)
+{
+ if ((whence != SEEK_SET) || (fd == 4711))
+ return -1; /* only those supported */
+ return VolumeSeek(offset);
+}
+
+#define open OpenVolume
+#define close CloseVolume
+#define read(a,b,c) ReadVolume(b,c)
+#define write(a,b,c) WriteVolume(b,c)
+#else
+loff_t llseek(int fd, loff_t offset, int whence)
+{
+ return (loff_t) lseek64(fd, (off64_t) offset, whence);
+}
+#endif
+
+void fs_open(char *path, int rw)
+{
+ struct stat stbuf;
+
+ if ((fd = open(path, rw ? O_RDWR : O_RDONLY)) < 0) {
+ perror("open");
+ exit(6);
+ }
+ changes = last = NULL;
+ did_change = 0;
+
+#ifndef _DJGPP_
+ if (fstat(fd, &stbuf) < 0)
+ pdie("fstat %s", path);
+ device_no = S_ISBLK(stbuf.st_mode) ? (stbuf.st_rdev >> 8) & 0xff : 0;
+#else
+ if (IsWorkingOnImageFile()) {
+ if (fstat(GetVolumeHandle(), &stbuf) < 0)
+ pdie("fstat image %s", path);
+ device_no = 0;
+ } else {
+ /* return 2 for floppy, 1 for ramdisk, 7 for loopback */
+ /* used by boot.c in Atari mode: floppy always FAT12, */
+ /* loopback / ramdisk only FAT12 if usual floppy size, */
+ /* harddisk always FAT16 on Atari... */
+ device_no = (GetVolumeHandle() < 2) ? 2 : 1;
+ /* telling "floppy" for A:/B:, "ramdisk" for the rest */
+ }
+#endif
+}
+
+/**
+ * Read data from the partition, accounting for any pending updates that are
+ * queued for writing.
+ *
+ * @param[in] pos Byte offset, relative to the beginning of the partition,
+ * at which to read
+ * @param[in] size Number of bytes to read
+ * @param[out] data Where to put the data read
+ */
+void fs_read(loff_t pos, int size, void *data)
+{
+ CHANGE *walk;
+ int got;
+
+ if (llseek(fd, pos, 0) != pos)
+ pdie("Seek to %lld", pos);
+ if ((got = read(fd, data, size)) < 0)
+ pdie("Read %d bytes at %lld", size, pos);
+ if (got != size)
+ die("Got %d bytes instead of %d at %lld", got, size, pos);
+ for (walk = changes; walk; walk = walk->next) {
+ if (walk->pos < pos + size && walk->pos + walk->size > pos) {
+ if (walk->pos < pos)
+ memcpy(data, (char *)walk->data + pos - walk->pos, min(size,
+ walk->size
+ - pos +
+ walk->pos));
+ else
+ memcpy((char *)data + walk->pos - pos, walk->data,
+ min(walk->size, size + pos - walk->pos));
+ }
+ }
+}
+
+int fs_test(loff_t pos, int size)
+{
+ void *scratch;
+ int okay;
+
+ if (llseek(fd, pos, 0) != pos)
+ pdie("Seek to %lld", pos);
+ scratch = alloc(size);
+ okay = read(fd, scratch, size) == size;
+ free(scratch);
+ return okay;
+}
+
+void fs_write(loff_t pos, int size, void *data)
+{
+ CHANGE *new;
+ int did;
+
+ if (write_immed) {
+ did_change = 1;
+ if (llseek(fd, pos, 0) != pos)
+ pdie("Seek to %lld", pos);
+ if ((did = write(fd, data, size)) == size)
+ return;
+ if (did < 0)
+ pdie("Write %d bytes at %lld", size, pos);
+ die("Wrote %d bytes instead of %d at %lld", did, size, pos);
+ }
+ new = alloc(sizeof(CHANGE));
+ new->pos = pos;
+ memcpy(new->data = alloc(new->size = size), data, size);
+ new->next = NULL;
+ if (last)
+ last->next = new;
+ else
+ changes = new;
+ last = new;
+}
+
+static void fs_flush(void)
+{
+ CHANGE *this;
+ int size;
+
+ while (changes) {
+ this = changes;
+ changes = changes->next;
+ if (llseek(fd, this->pos, 0) != this->pos)
+ fprintf(stderr,
+ "Seek to %lld failed: %s\n Did not write %d bytes.\n",
+ (long long)this->pos, strerror(errno), this->size);
+ else if ((size = write(fd, this->data, this->size)) < 0)
+ fprintf(stderr, "Writing %d bytes at %lld failed: %s\n", this->size,
+ (long long)this->pos, strerror(errno));
+ else if (size != this->size)
+ fprintf(stderr, "Wrote %d bytes instead of %d bytes at %lld."
+ "\n", size, this->size, (long long)this->pos);
+ free(this->data);
+ free(this);
+ }
+}
+
+int fs_close(int write)
+{
+ CHANGE *next;
+ int changed;
+
+ changed = ! !changes;
+ if (write)
+ fs_flush();
+ else
+ while (changes) {
+ next = changes->next;
+ free(changes->data);
+ free(changes);
+ changes = next;
+ }
+ if (close(fd) < 0)
+ pdie("closing file system");
+ return changed || did_change;
+}
+
+int fs_changed(void)
+{
+ return ! !changes || did_change;
+}
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